Neutralization of SARS-CoV-2 variants by rVSV-ΔG-spike-elicited human sera

The emergence of rapidly spreading variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a major challenge to the ability of vaccines and therapeutic antibodies to provide immunity. These variants contain mutations at specific amino acids that might impede vaccine efficacy. BriLife® (rVSV-ΔG-spike) is a newly developed SARS-CoV-2 vaccine candidate currently in Phase II clinical trials. It is based on a replication competent vesicular stomatitis virus (VSV) platform. rVSV-ΔG-spike contains several spontaneously-acquired spike mutations that correspond to SARS-CoV-2 variants’ mutations. We show that human sera from BriLife® vaccinees preserve comparable neutralization titers towards alpha, gamma and delta variants, and show less than 3-fold reduction in neutralization capacity of beta and omicron compared to the original virus. Taken together, we show that human sera from BriLife® vaccinees overall maintain neutralizing antibody response against all tested variants. We suggest that BriLife® acquired mutations may prove advantageous against future SARS-CoV-2 VOCs.